Field of the Disclosure
The invention relates to fluid separation systems and methods. More particularly, the invention relates to systems employing spinning membranes for fluid separation and methods for operating such systems.
Description of Related Art
Various blood processing systems now make it possible to collect particular blood constituents, instead of whole blood, from a blood source such as, but not limited to, a container of previously collected blood or other living or non-living source. Typically, in such systems, whole blood is drawn from a blood source, a particular blood component or constituent is separated, removed, and collected, and the remaining blood constituents are returned to the blood source. Removing only particular constituents is advantageous when the blood source is a human donor, because potentially less time is needed for the donor's body to return to pre-donation levels, and donations can be made at more frequent intervals than when whole blood is collected. This increases the overall supply of blood constituents, such as plasma and platelets, made available for transfer and/or therapeutic treatment.
Whole blood is typically separated into its constituents (e.g., red cells, platelets, and plasma) through centrifugation, such as in the AMICUS® separator from Fenwal, Inc. of Lake Zurich, Ill., or other centrifugal separation devices, or a spinning membrane-type separator, such as the AUTOPHERESIS-C® and AURORA® devices from Fenwal, Inc. Such separation devices typically comprise a fluid circuit having a separation chamber, sources or containers of various solutions, and collection containers that are interconnected by tubing and which is mounted onto a durable hardware component that includes pumps, clamps, and sensors that are automatically operated by a programmable controller to perform the desired blood separation procedure.
In the context of an apheresis procedure, in which whole blood is withdrawn from a donor or patient and a concentrated blood component is re-infused, certain efficiencies and enhancement of donor comfort and safety can be achieved if the draw and return phases of the procedure are divided into a series of sequentially-performed draw and return cycles. This causes the donor's blood volume to vary less over the course of the procedure, while maintaining the total volume of fluid withdrawn from and returned to the donor.
When the apheresis procedure is being performed with a single donor line that is used for both the draw and return phases of the procedure, the donor line must be cleared or primed prior to each commencement of the draw phase. In addition, during the return phase, if air is detected in the donor line, the return of fluid to the donor is suspended to permit purging air from the donor line, after which the return phase may be continued. By way of the present disclosure, a method is provided for performing the return phase of a blood separation procedure in which, in the case of air detection, the draw phase are may be immediately initiated, resulting in a more efficient performance of the procedure with reduced procedure time.